Developing agent dispersions



United States Patent 3,518,088 DEVELOPING AGENT DISPERSIONS Joseph S. Dunn and Albert C. Smith, Jr., Rochester,

N.Y., assignors to Eastman Kodak Company, Rochester, N.Y a corporation of New Jersey No Drawing. Continuation of application Ser. No. 514,697, Dec. 17, 1965. This application May 7, 1969, Ser. No. 824,741

Int. Cl. G03c 1/04 U.S. Cl. 96--114 Claims ABSTRACT OF THE DISCLOSURE Dispersions of silver halide developing agents such as developing agents which are insoluble in Water are prepared by mixing the developing agent with a non-proteinaceous, alkali permeable, synthetic, film-forming, high molecular Weight polymer either in a Water immiscible solvent for the polymer or in a latex of the polymer. The developer dispersion is incorporated in a gelatin lightsensitive, silver halide photographic emulsion.

This application is a continuation of Dunn and Smith, US. application Ser. No. 514,697 filed Dec. 17, 1965.

This invention relates to elements containing incorporated developing agents and, in particular, one aspect of this invention relates to photographic elements containing polymeric dispersions of developing agents.

The incorporation of developing agents directly into processing webs or in photographic elements comprising at least one silver halide emulsion layer is known. Heretofore said developing agents have been incorporated in the photographic layers via conventional techniques, i.e., soluble developing agents have been added in a suitable solvent or mixture thereof and insoluble developing agents have been added as colloid milled particles or slurries thereof or dispersed in tiny globules of a water-insoluble crystalloidal coupler solvent as described, for example, in .legllley and Vittum US. Pat. 2,322,027, issued June 15,

It is also known to incorporate in silver halide emulsions polymeric binders either alone or admixed with gelatin and also to incorporate in these binders insoluble developing agents which are dispersed in a crystalloidal coupler solvent. However, the developers have a preferential afiinity for the coupler solvent, and the coupler solvent is retained in the emulsion after it has been coated on a suitable support.

Although useful, the above systems have exhibited certain disadvantages. Thus, the dissolved soluble developing agents once added to the photographic elements are free to wander through the material and result in a non uniform dispersion. In addition, the large volume of solvent, especially non-polar solvent usually required for dissolution of these agents, has a tendency to effect the photographic elements adversely. The milled dispersions of insoluble developing agents have a tendency to lose some of their developing activity and/ or add to the graininess of the photographic image when incorporated into photographic silver halide emulsion layers and also are not uniformly dispersed, while the oily coupler solvents used in other dispersions have a decided tendency to soften the photographic layers unduly and, in addition, possess low storage stability.

We have now found a method of preparing polymeric dispersions of developing agents which overcomes the disadvantages exhibited by the use of prior methods of incorporating developing agents into photographic compositions.

It is an object of this invention to provide photographic icecompositions containing therein polymeric dispersions of developng agents.

It is another object of this invention to provide photographic compositions containing alkali-permeable polymeric dispersions of silver halide developing agents.

It is a further object of this invention to provide photographic silver halide elements containing incorporated, alkali-permeable polymeric dispersions of silver halide developing agents.

It is an additional object of this invention to provide a method of uniformly dispersing: developing agents in polymeric materials.

The accomplishment of these and other objects will be apparent from the following description and examples which are meant to illustrate our invention and not to limit the scope thereof.

In general, the polymers useful in our invention are high molecular weight, film-forming polymers and may be either of a hydrophilic or hydrophobic nature. Preferably, however, they are of a hydrophilic nature to insure compatibility with gelatin when mixed therewith and also for ease of permeability of alkaline processing solutions. Although the amount of polymer-developer dispersion used will vary for different purposes as is known in the art, typical preparations wherein the polymer-developer dispersion is utilized in a gelatin composition advantageously contain from about 5% to 100% of polymer based on the weight of the gelatin. A useful range of developer-topolymer in the preparation of the dispersions of our invention has been found to be from about one part developer to one part of polymer to a ratio of from about one part develper to five parts polymer.

In one embodiment of our invention, a relatively hydrophilic, film-forming polymer and a developing agent are dissolved in a common low-boiling, water-immiscible organic solvent, such as ethyl acetate, and the resulting solution is thoroughly mixed with strong agitation with an aqueous medium containing a hydrophilic colloid, such as gelatin, to form an oil-in-water type emulsion having fine droplets of the hydrophobic liquid comprising dissolved polymer and developing agent dispersed throughout the aqueous phase. This dispersion is set, for example, by chilling, and substantially all of the solvent is removed therefrom by evaporation at room temperature or by Washing. The steps of setting and solvent removal result in the formation of minute, discrete, solid particles comprising polymer and developing agent.

In another embodiment of our invention, the developing agent is added to a latex of the relatively hydrophilic film-forming polymer employing water as the dispersing medium. The developing agent is absorbed by the polymer particles so that a solvent for the developing agent is not required. The latex is then added with strong agitation to an aqueous medium containing a hydrophilic colloid such as gelatin. In this embodiment, since water is the dispersing medium, it is not necessary to remove the solvent as in the embodiment described above. The hydrophilic colloid dispersion to which the polymeric dispersion is mixed may be a simple gelatin solution or it may be a light-sensitive silver halide emulsion. For some purposes, it may be desirable to incorporate the developer dispersion in a contiguous layer or in some layer on a support which is non-light sensitive. For other purposes, the polymeric dispersion may be incorporated in the silver halide emulsion.

The polymers useful in our invention are non proteinaceous alkali-permeable film-forming, high-molecular weight synthetic polymers, hydrophilic in nature or in the form of latices formed by emulsion polymerization procedures. Typical polymers useful in our invention are interpolymers in which the major component represents 3 hydrophobic monomer units such as vinyl acetal, alkyl acrylate, alkyl methacrylate or cellulose ester units. Excellent results are obtained with C to C alkylacrylate or methacrylate polymers containing minor proportions of acidic monomers such as acrylic acid, itaconic acid, acryloxyalkane-sulfonic acids, etc.

Typical polymers useful in our invention, in addition to those described in the examples, are as follows:

(1) Poly(viny1 acetal) (2) Cellulose acetate hydrogen phthalate (3) Butyl acrylate-3-acryloxybutane-l-sulfonic acid (85:15) sodium salt (4) Butyl acrylate-3-acryloxybutane-l-sulfonic acid (95:5) sodium salt (5) Butyl acrylate-3-acryloxypropane-I-sulfonic acid (85:15) sodium salt ('6) Butyl acrylate-3-acryloxypropane-l-sulfonic acid (95 :5) sodium salt (7) Butyl acrylate-acrylamide (85:15)

(8) Butyl acrylate-acrylamide (95:5

(9) Methyl acrylate-acrylic acid (90:10)

(10) Methyl acrylate-acrylic acid (95 :5)

(11) Stearyl methacrylate-acrylic acid (85:

(12) Butyl acrylate-stearyl methacrylate-acrylic acid (13) Butyl acrylate-stearyl methacrylate-acrylic acid l4) Butyl acrylate-N-cyanoacetyl-N'-rnethacrylyl hydrazine (95:5)

( 15 Butyl acrylate-N-cyanoacetyl-N'-methacrylyl hydrazine (90:10)

(16) Butyl acrylate-2-methyl-5-vinylpyridine-acrylic acid (l7) Butyl acrylate-2-methyl-5-vinylpyridine-acrylic acid (18) Butyl acrylate-acrylic acid (98.2) sodium salt (19) Butyl acrylate-cetyl vinyl ether-acrylic acid (20) Poly(vinyl phthalate) (21) Poly(vinyl butyl succinate) (22) Butyl acrylate-stearyl methacrylate-acrylic acid (23) Butyl acrylate-stearyl methacrylate-acrylic acid (24) Butyl acrylate-stearyl methacrylate-acrylic acid (25 Butyl acrylate-stearyl methacrylate-acrylic acid (26) Butyl acrylate-stearyl methacrylate-acrylic acid The polymer-developer dispersions of our invention may be utilized in various photographic elements, containing incorporated developing agents, e.g., the elements described in Yackel et al. U.S. Pats. 2,596,756; 3,143,414; 3,146,104; 3,148,063; Weyerts and Salminen U.S. Pat. 3,146,102; Abbott et al. U.S. Pat. 3,147,500; Tregillus et al. U.S. Pat 3,179,517 and the heat processed elements of Stewart et a1. Belgian Pat. 621,608. The developer-polymer dispersions of our invention have been found to be particularly useful in elements designed for the production of relief-printing plates, e.g. those described in Staehle and Baxter U.S. patent application Ser. No. 269,345, now US. Pat. 3,271,150, filed Apr. 1, 1963, and in Staehle and Smith U.S. patent application Ser. No. 431,035, now U.S. Pat 3,271, 151, filed Feb. 8, 1965.

The light-sensitive elements described in the above two applications contain an incorporated tanning developing agent of the type described in U.S. Pats. 2,685,510; 2,716,059 and 2,751,295. Since the developing agent is Water-insoluble, it is dissolved in a substantially waterinsolu'ble organic crystalloidal solvent having a boiling point above about 175 C.

We have found that the oily nature of these developer- 4 oil solvent dispersions tends to soften the coated layers utilized in relief printing plate elements.

We have now found that the elements described in US. Ser. No. 431,035, now U.S. Pat. 3,271,151, may be further improved by adding the tanning developer thereto in the form of a polymeric dispersion, as hereinafter described, eliminating the need for oil solvent dispersions thereby producing a more rigid relief printing plate of extended plate life.

The following examples are intended to illustrate our invention, but not to limit it in any Way.

EXAMPLE 1 To a fine-grain blue-sensitive silver chloride photographic emulsion was added a developer dispersion of the type described in Example 4 of U.S. Pat. 3,146,104. Further additions comprised conventional addenda such as coating aids, antifoggants, etc.

The emulsion was then coated on a film support to yield a silver coverage of 165 mg. per sq. ft. and a gelatin coverage of 490 mg. per sq. ft. Number 1 was assigned to this coating. Additional coatings 2 and 3 differed only in that they contained, respectively, the developer dispersions 1 and 2 below in place of the oil solvent developer dispersion. In all cases sufiicient dispersion was utilized to yield about 50 grams of 4-phenyl catechol per silver mole.

Dispersion 1.-Developer to polymer=1:l

Grams (A) 4-phenyl catechol 2.05

20% solution of butyl acrylate-acrylic acid :15) in ethyl acetate 10.25 (B) 10% gelatin solution (aqueous) 25.80 15.34% aqueous saponin solution 0.62

A was added to B at 50 C. with mechanical agitation. The dispersion was made by passing this mixture 5 times through a colloid mill after which it was chill set, noodled and dried. Particle size was approximately 1 to 2 microns.

Dispersion 2.-Developer to polymer=1:2

As in Dispersion 1 above except that 1.025 grams of 4-phenyl catechol were used. The dispersion was made as described above.

These coatings were tested and the results indicated that coatings 2 and 3 were considerably harder than coating 1. Coating 3 produced relief printing plates and gravure printing plates having extremely long wear properties.

EXAMPLE 2 The following coatings were made in a manner similar to that described in Example 1 except for a variation in the incorporated developer dispersion as described below.

Ratio Developer dispersion Polymer: Developing Agent: Gelatin Developer dispersions; All of "the following dispersions,

Beneficial results similar to those noted in Example 1 were also achieved with the above coatings.

Dispersion 3.Developer to polymer=1:4

Grams (A) 4-phenyl catechol 2.5

20% solution of butyl acrylate-acrylic acid (85:15) in ethyl acetate 50.0 (B) 10% gelatin solution 125.0 15.34% saponin solution 3.1

Dispersion 4.-Developer to polymer=1:4 As in Dispersion 3 except that 75 grams of a 10% gelatin solution was used.

Dispersion 5.Developer to polymer=1z1 Grams (A) 4-phenyl catechol 2.5

20% solution of butyl acrylate-acrylic acid (95 :5) in ethyl acetate 12.5 Ethyl acetate 12.5 (B) gelatin solution 50.0 15.34% saponin solution 1.24

Dispersion or-Developer to polymer=1zl (A) 4-phenyl catechol 2.5

% solution of butyl acrylate-acrylic acid (95:5) in ethyl acetate 12.5 Ethyl acetate 50.0 (B) 10% gelatin solution 125.0 15.34% saponin solution 3.10

Dispersion 7.-Developer to polymer=1:l

(A) 4-phenyl catechol 2.5

20% solution of butyl acrylate (100) in ethyl acetate 12.5 Ethyl acetate 20.0 (B) 10% gelatin solution 125.0 15.34% saponin solution 3.1

Dispersion 8.Developer to po1ymer=1 :2

Grams (A) 4-phenyl catechol 1.7

10% solution of poly(vinyl-acetalphthalate) in ethyl acetate 34.0 (B) 10% gelatin solution 51.6 15.34% saponin solution 1.24

Dispersion 9.Developer to polymer=1:1

Grams (A) 4-phenyl catechol 2.05

10% solution of poly(vinyl-acetalphthalate) in ethyl acetate 20.5 (B) 10% gelatin solution 51.6 15.34% saponin solution 1.24

Dispersion 10.Developer to polymer=1:1

Grams (A) 4-phenyl catechol 2.05 10% solution of ethyl cellulose phthalate in cyclohexanone 20.5 (B) 10% gelatin solution 25.8 15.34% saponin solution 1.24

A was added to B at 50 C. with the aid of mechanical agitation. A dispersion was prepared by passing the mixture 5 times through a colloid mill after which it was chillset, noodled, washed in cold water for 6 hours and dried.

Dispersion 11.Developer to polymer=l :2

Grams (A) 4-pheny1 catechol 2.05

10% solution of ethyl cellulose phthalate in cyclohexanone 41.00 (B) 10% gelatin solution 51.60 15.34% saponin solution 1.24

Dispersion l2.Developer to polymer=1:1

Grams (A) 4-pheny1 catechol 2.05

20% solution of Lucite 2044 (Du Pont) in ethyl acetate 10.25 (B) 10% gelatin solution 51.60 15.34% saponin solution 1.24

Lucite is a trade name for polymerized methyl methacrylate.

Dispersion l3.-Developer to polymer=l:2

Grams (A) 4-phenyl catechol 2.05

20% solution of Lucite (Du Pont) in ethyl acetate 20.50

(B) 10% gelatin solution 51.60

15.34% saponin solution 1.24

Dispersion 14.--Developer to polymer=1 :4

Grams (A) 4-phenyl catechol 2.05

20% solution of Lucite (Du Pont) in ethyl acetate 41.00 (B) 10% gelatin solution 51.60 15.34% saponin solution 1.24

The following examples illustrate the utility of various types of developing agents in our invention.

EXAMPLE 3 Dispersion 15.--Developer to polymer: 1 :2

Grams (A) Chlorohydroquinone 2.05

21.8% solution of butyl acrylate-acrylic acid (:15) in ethyl acetate 18.80

(B) 10% gelatin solution 51.60

15.34% saponin solution 1.24

Dispersion made as described in Example 1.

Dispersion 16 Similar to Dispersion 15 except that hydroquinone was utilized as the developing agent.

Dispersion 17 Coating: Developer dispersion or solution (g. per yo silver mole) A Dispersion 15 (11.3 g.).

B Dispersion 16 (11.3 g.)+]Dispersion 17 (1.1 g.).

C 4.1% methanolic solution of chlorohydroquinone (50 g.).

D .4.1%. methanolic solution of hydroquinone (50 g.)+2.05% methanolic solution of l-phenyl- 3-pyrazolidone (10 g.).

Tests of these coatings as relief printing plates indicated that Coatings A and B were considerably harder and produced longer wear plates than did Coatings C and D with equallygood images.

EXAMPLE 4- A roll of hardener-free photographic paper stock (10" x approximately 500) was dip-coated in a dispersion of the following composition.

Methylene chloride-82 lbs.

Lecithin-0.2 oz.

Polycarbonate resin (Lexan)-l lbs. Titanium oxide pigment (Unitane)--7 lbs.

8 (2) The element is then stabilized by washing oil the unexposed emulsion by means of a series of spray nozzles that direct a Warm (100-105" F.) water spray to the surface of the emulsion as it passes through the machine; (3) The card is dried finally by directing a stream of The a er support was passed through the above dispersion at about 4-6 feet per minute with approximately 5 hlgh pressure alr agamst the card Sulface' 40 inches of paper being immersed at one time. As the EXAMPLE 5 impregnated support emerged from the dispersion, the excess liquid was removed from the surface by threaded This example gives the results of wear tests on coatcomb bars and warm air was used for drying the supings similar to those described in Example 1 except that port. A total weight of approximately 4.1 g./ft. (comthey also contain finely divided hard substances (as debined Unitane and Lexan) was impregnated in the paper scribed in Staehle and Smith application Ser. No. 431,- stock. The support was then subbed with a conventional 035) at a coverage approximately equal to that of the gelatin-nitrate sub. gelatin. The coatings are as follows:

A 9 gelatm pad apphqd over the Sim-layer (A) Using the emulsion of Example 1, the developer as a two-mch wide center stripe (this was so designed to f 11 d th fi 1 d h d give a final one-inch wide longitudinal edge stripe after llperslon o f i' b an e P y m e d at die cutting the tabulating cards). The gelatin pad was g arm to a a coating was e at 2 mg. of silver/sq. ft. and 395 mg. of gelatin/sq. ft. applied at approximately 5 mg. of gelatin/ft. and, as an B A A b 248 ft d 593 f optional feature, could contain an antihalation dye or pig- 1 utfwl S1 ver an 0 ment. An ortho-sensitized, unhardened silver chlorobroi h 30 i1 f mide emulsion containing approximately 50 g. of 4-phenyls Wit 3 of S ver and 790 catechol/Ag mole was coated over the above gelatin of ghelatm/sq'fi' pad. The emulsion also contained a coating aid, an anti- (D) AS t i q of Examp but Wlth the addmon foggant and an antihardener and was coated to give of the finely dlvided hard substances referred to above. proximately 100 mg. Ag/ft. and 250 mg. gelatin/ftfi. Coating of the above light-sensitive emulsion were The emulsion and/or the' gelatin pad Can be Coated f laminated to a lacquer-coated steel plate for evaluation water-methanol miXwIeS to improve physical coating propof the wear properties of the plate on 3, Harris Wraperties. around printing press. Exposure was made to an original The coated paper was die cut to the proper data card containing fine serif type and solid panels on each strip dimensions. Such cards were exposed and were then procof plate. The exposed plates were activated in an alkaline essed in an alkaline activator. The unhardened emulsion solution pH 11.0 for 6 minutes, washed with a spray of was removed with a warm-water wash and the permanent warm water to remove the unhardened emulsion, and photographic image became an integral part of the tabur dried with warm air. Strips of each of the four plates lating card. Such cards could be prepared with the prewere set up on the press with parts A and B on one side scribed total thickness, and dimensional stability was exof the press and parts C and D on the other. The follow cellent. The easily processed cards dried rapidly since ing tabulation shows the extent of wear observed on the relatively small areas of highly hardened gelatin repress plates during the press run.

Observed Emulsion Wear Part A Part B Part 0 Part D Number 0! impressions:

0 No wean-.. No wear-... No wean... No wear. 000. ..do -.do d Do. 20,000. Sl. wear do do Considerable wear. 62,000. 20% gone 10% gone.-- 30% gene... Emulsion gone.

mained after wash-01f. The cards exhibited no tendency The bold type and solids showed no wear on the press to curl because the remaining gelatin film was discontinusheets. Results achieved as above by an actual press run ous and the images could be readily removed by the use indicate diiferences between modifications which affect of a damp pencil eraser. the press life.

Grams The polymer-developer dispersions of our invention (A) 4- 1 1cath 1 2.05 may be utilized in various photographic silver halide Ethyl cellulose phthalate (Eastman Organic emulsions including direct positive examples, for exam- No. 7484) (10% in cyclohexanone) 20.5 ple, direct positive emulsions of the type described in (B) Gelatin (10%) 25.8 Kendall and Hill U.S. Pat. 2,541,472 and Fallesen U.S.

Saponin (15.34% solution) 1.24 Pat. 2,497,875.

1 The 4-pheny1ea tech0l was added to the emulsion in the In addition to the Polymer-developer dispersions of our form of a dispersion of e followi g co position: invention, there may be utilized in the silver halide emul- Solution A was added to 5 1 5 B at 50 C h good sions various other conventional addenda such as sensistirring, after which it was passed 5 times through a colfilers antifoggants, hardeners, Coating aids, loid mill, and it was then chill-set noodled, washed in Various Silver Salts y be used as the Sensitive t cold Water f 6 hours and dried such as silver bromide, silver iodide, silver chloride, or

The emulsion, present in stripe form, on the tabulating mixed silver halides such as silver chlorobromide or silcard allows rapid, automatic processing by attaching the ver bromolodide. The polymer-developer dispersions of card, on the long end opposite the emulsion-coated edge 0 Invention may be used in emulsions intended for between two endless transport belts and passing the card Color P p y for p emulsions containing thus attached through the following automatic machine color'forming cQUPICI'S emulsions to be developtid y sequence: solutions containing couplers or other color-generating (l) The activator solution is applied to the surface of materials, emulsions 0f the mixed-Packet yp c as the emulsion strips by a pump which supplies activator scribed in GOdOWSkY issued to the card, releasing the developer in the emulsion which 1955; or emulsions of the mixed-grain type, such as dedevelops and hardens the image areas;

scribed in Carroll and Hanson U.S. Pat. 2,592,243, issued Apr. 8, 1952. These dispersions can also be used in emulsions which form latent images predominantly on the surface of the silver halide crystal or in emulsions which form latent images predominantly inside the silver halide crystal, such as those described in Davey and Knott US. Pat. 2,592,250, issued Apr. 8, 1952.

The dispersions may also be used in emulsions intended for use in diffusion transfer processes which utilize the undeveloped silver halide in the non-image areas of the negative to form a positive by dissolving the undeveloped silver halide and precipitating it on a receiving layer in close proximity to the original silver halide emulsion layer. Such processes are described in Rott US. Pat. No. 2,352,014, issued June 20, 1944, and Land U.S. Pats. 2,584,029, issued Jan. 29, 1952; 2,698,236, issued Dec. 28, 1954, and 2,543,181, issued Feb. 27, 1951; and Yackel et al. US. patent application Ser. No. 586,- 705, filed May 23, 1956, now US. Pat. 3,411,568. The dispersions may also be used in color transfer processes which utilize the diffusion transfer of an imagewise distribution of developer, coupler or dye, from a light-sensitive layer to a second layer, while the two layers are in close proximity to one another. Color processes of this type are described in Land U.S. Pats. 2,559,643, issued July 10, 1951, and 2,698,798, issued Jan. 4, 1955; Land and Rogers Belgian Pats. 554,933 and 554,934, granted Aug. 12, 1957; International Polaroid Belgian Pats. 554,212, granted July 16, 1957, and 554,935, granted Aug. 12, 1957; Yutzy US. Pat. No. 2,756,142, granted July 24, 1956, and Whitmore and Mader US. patent application Ser. No. 734,141, filed May 9, 1958.

The polymer-developer dispersions may also be used in emulsions intended for use in a monobath process such as described in Haist et al., US. Pat. 2,875,048, issued Feb. 24, 1959. As used herein and in the appended claims the term developing agent includes developing agent precursors which release active developing agent on treatment at high pH, e.g., with alkali combinations of these addenda may be used. The preferred polymeric vinyl compounds are homor or copolymers prepared from acrylic acid and esters thereof. These polymers are insoluble in water and can be readily dispersed in water and mixed with a suitable silver halide peptizer such as gelatin. Good results are achieved with polymers of alkyl acrylates or methacrylates which are obtained by homopolymerizing these monomers or interpolymerizing these monomers with each other or with different ethylenically unsaturated polymerizable compounds, containing one or more CH=C groups, or more particularly one or more CH C groups, to form water-insoluble addition polymers. In general, it is desirable to employ a polymeric vinyl compound which contains, in polymerized form, at least 65% preferably about 75 to about 95% by weight, of an alkyl acrylate or methacrylate, as exemplified by ethyl acrylate methyl acrylate, butyl acrylate, ethylmethacrylate, octyl methacrylate, and the like. Suitable ethylenically unsaturated comonomers which can be interpolymerized with these materials to form water-insoluble addition polymers include, for example, vinyl esters, amides, nitriles, ketones, halides, ethers, a,;3-1111Sfltl1l3t6d acids or esters thereof, olefins, diolefins and the like, as exemplified by acrylonitrile, methacrylonitrile, styrene, u-methylstyrene, vinyl chloride, vinylidene chloride, methyl vinyl ketone, vinyl acetate, fumaric, maleic and itaconic acid esters, 2-chloroethylvinylether, methylenemaleonitrile, acrylic acid, methacrylic acid, dimethylaminoethylmethacrylate, N- vinylsuccinimide, N vinylphthalimide, N-vinylpyrrolidone, butadiene, isoprene, vinylidene cyanide and the like. The polymeric vinyl compounds most useful'in the practice of this invention generally have an average molecular weight in the range of about 5000 to about 500,000.

A particularly useful class of vinyl polymers which can be employed in the practice of this invention are water-insoluble interpolymers of acrylates or methacrylates with acrylic acid and a sulfobetaine having the formula:

where R, R and R are each hydrogen or alkyl and R and R are each divalent saturated hydrocarbon radicals, desirably containing up to 12 carbon atoms. Suitable sulfobetaine monomers include, for example, 5,5,10- trimethyl-9-oxo'8-oxa-5-azonia-10-undecene-l sulfonate, 4-t-butyl-9-methyl-8-oxo-7-oxa-4-aZa-9-decene-1 sulfonic acid, 4,4,9 trimethyl 8-oxo-7-oxa-4-azonia-9-decene-1- sulfonate, and the like. The preferred polymers of this type contain, in polymerized form, at least 75%, preferably about 75 to about 93% by weight of acrylate or methacrylate up to about 15%, preferably about 5 to about 15%, by weight, acrylic acid and up to about 10%, preferably about 2 to about 10% by weight, of the sulfobetaine.

A very convenient method for preparing the sulfobetaine monomers used in preparing the aforementioned preferred class of polymeric vinyl compounds comprises reacting the appropriate amino alkyl ester of an unsaturated carboxylic acid with the appropriate sultone. Such a reaction can be carried out in the presence of an organic solvent such as acetonitrile, a liquid hydrocarbon or a ketone such as acetone at temperatures up to about 100 C., preferably 50 to about C. In general, the reaction is complete in less than 8 hours, often in about 2 to about 6 hours. The reaction is not pressure dependent and therefore superatmospheric or subatmospheric pressures can be employed. The resulting sulfobetaine can be isolated by conventional procedures. The reactants are generally employed in stoichiometric concentrations al- 'useful in the practice of this invention is the interpolymers of alkyl acrylates or methacrylates with sulfoesters having the formula:

where R is hydrogen or alkyl, R; has its valence bonds on different carbon atoms and is a divalent hydrocarbon radical or aliphatic divalent hydrocarbon radical in which a carbon chain joining the oxygen and sulfur atoms in the formula shown is interrupted by at least one oxygen and/0r sulfur radical and M is a cation. Suitable R groups include hydrogen or any of the alkyl radicals, preferably alkyl radicals containing up to about 12 carbon atoms, often 1-8 carbon atoms, as exemplified by methyl, ethyl, propyl, pentyl, octyl, dodecyl and the like. R has its valence bonds on different carbon atoms and can be a hydrocarbon radical or it can be an aliphatic hydrocarbon radical in which a chain of carbon atoms joining the oxygen and sulfur atoms in the formula shown above is interrupted by an atom from Group VI A of the Periodic Table having an atomic weight less than about 33, i.e., at least one O- and/or -S radical interrupts the carbon chain. Where R is hydrocarbon, it can be any aliphatic, cycloaliphatic or aromatic radical and will generally contain up to about 12 carbon atoms. Preferred hydrocarbon R radicals are alkylene radicals, generally those containing 24 carbons. R can also be a divalent alipthatic hydrocarbon radical in which there is a O and/or -S- radical and generally contains up to 12 carbon atoms. Such R radicals can, therefore, be saturated or unsaturated, although saturated divalent alkylene groups in which the carbon chain is interrupted by oxygen and sulfur atoms are preferred. Suitable R radicals include, for example, ethylene, 1,3-propylene, 1,2-propylene, tetramethylene 13 isobutylene pentamethylene hexamethylene octamethylene, phenylene, bisphenylylene, naphthylene, cyclopentylene, cyclohexylene, Z-butenylene, butynylene, 2-oxatrimethylene, 3-thiapentamethylene, and the like. M is a cation, as exemplified by hydrogen, an alkali metal such as sodium or potassium, ammonium, the cation of an organic amine such as triethylamine, diethanolamine and the like.

The sulfoesters can be prepared using any method known to be suitable for this purpose. For example, US. Pat. 2,923,734, issued Feb. 2, 1960, discloses the preparation of such esters by the reaction of an a-methylene carboxylic acid with an aliphatic hydroxy sulfonic acid while US. Pat. 3,024,221, issued Mar. 6, 1962, discloses a method for preparing the sulfoester by reacting the appropriate acyl halide with the salt of the hydroxy sulfonic acid. Examples of hydroxy sulfonic acids and their salts) that can be employed to form the sulfoesters are Z-hydroxyethane sulfonic acid, 2-hydroxy-l-propane sulfonic acid, l-hydroxy-Z-butane sulfonic acid, Z-hydroxycyclohexane sulfonic acid, p-phenolsulfonic acid, 2-(2- hydroxyethoxy)ethane-l-sulfonic acid, 2-(2-hydroxyethy1- 'thio)ethane-1-sulfonic acid, 4-hydroxy-2-butene-l-sulfonic acid, 4-hydroxy-2-butyne-l-sulfonic acid and the like. a-Methylene carboxylic acids or acyl halides include acrylic acid, methacrylic acid, -butylacrylic acid, acryloyl chloride, methacryloyl bromide, -hexylacryloyl chloride and the like. The preferred class of polymers of the sulfoesters generally contains, in polymeric form, at least 65%, preferably about 85 to about 90%, by weight, of the alkyl acrylate or methacrylate and up to about 15%, preferably about to about by weight, of the sulfoester.

The temperature at which the polymeric vinyl compounds employed in the practice of this invention are prepared is subject to wide variation since this temperature depends upon such variable features as the specific monomer used, duration of heating, pressure employed and like considerations. However, the polymerization temperature generally does not exceed about 100 C., and most often, is in the range of about 50 to about 90 C. The polymerization can be carried out in suitable solvents or diluents for example, water or mixtures of water with water miscible solvents, as exemplified by methanol, ethanol, propanol, isopropyl alcohol, butyl alcohol and the like. The pressure employed in the polymerization, if any, is usually only sufficient to maintain the reaction mixture in liquid form, although either superatmospheric or subatmospheric pressures can be used. The concentration of polymerizable monomer in the polymerization mixture can be varied widely with concentrations up to about 40 percent, by Weight, and preferably about to about percent, by weight, based on the Weight of the vehicle being satisfactory. Suitable catalysts for the polymerization reaction include, for example, the free radical catalysts, such as hydrogen peroxide, cumene hydroperoxide, water soluble azo type initiators, and the like. In redox polymerization systems, the usual ingredients can be employed. If desired, the polymer can be isolated from the reaction vehicle by freezing, salting out, coagulation or by using other separation procedure suitable for this purpose.

The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

We claim:

1. A developer dispersion selected from the class consisting of (1) an oil-in-Water emulsion comprising fine droplets dispersed throughout an aqueous phase of a lowboiling, water immiscible solvent having dissolved therein a non-proteinaceous, alkali permeable, synthetic, filmforming, high molecular Weight polymer and a waterinsoluble silver halide developing agent and (2) an aqueous latex of a non-proteinaceous, alkali permeable, synthetic, film-forming, high molecular weight polymer having a water-insoluble silver halide developing agent absorbed by the said polymer particles.

2. A dispersion of claim 1 wherein the polymer is hydrophilic.

3. A dispersion of claim 1 wherein the polymer is a latex.

4. A dispersion of claim 1 wherein the polymer is a hydrophilic polymer having a molecular weight of from about 5,000 to about 500,000.

5. A photographic element comprising a support having thereon said dispersion of claim 1.

6. A photographic element comprising a support having thereon the said dispersion of claim 2.

7. A photographic element comprising a support havin g thereon the said dispersion of claim 3.

8. A photographic element comprising a support having thereon at least one layer comprising a mixture of hydrophilic colloid and a developer dispersion selected from the class consisting of 1) and oil-in-water type emulsion comprising fine droplets dispersed throughout an aqueous phase of a low-boiling, water immiscible solvent having dissolved therein a non-proteinaceous, alkali permeable, synthetic, film-forming, high molecular Weight polymer and a Water-insoluble silver halide developing agent and (2) an aqueous latex of a non-proteinaceous, alkali permeable, synthetic, film-forming, high molecular weight polymer having a water-insoluble silver halide developing agent absorbed by the said polymer particles.

9. An element of claim 8 having on the said support at least one silver halide emulsion.

10. A light-sensitive, silver halide photographic composition comprising a mixture of hydrophilic colloid and a developer dispersion selected from the class consisting of (1) an oil-in-water type emulsion comprising fine droplets dispersed throughout an aqueous phase of a low-boiling, water immiscible solvent having dissolved therein a non-proteinaceous, alkali permeable, synthetic, film-forming, high molecular weight polymer and a waterinsoluble silver halide developing agent and (2) an aqueous latex of a non-proteinaceous, alkali permeable, synthetic, film-forming, high molecular weight polymer having a water-insoluble silver halide developing agent adsorbed by the said polymer particles.

11. A photographic composition of claim 10 wherein the polymer is hydrophilic.

12. A composition of claim 10 wherein the polymer is a latex.

13. A composition of claim 10 wherein the polymer is a hydrophilic polymer having a molecular weight of from about 5,000 to about 500,000.

14. A photographic composition of claim 10 wherein the photographic composition is a silver halide emulsion.

15. A photographic element comprising a support having thereon the composition of claim 10.

16. A photographic element comprising a support having thereon the composition of claim 11.

17. A photographic element comprising a support having thereon at least one layer comprising a mixture of gelatin and a developer dispersion selected from the class consisting of (1) an oil-in-water type emulsion comprising fine droplets dispersed throughout an aqueous phase of a low-boiling, water immiscible solvent having dissolved therein a non-proteinaceous, alkali permeable, synthetic, film-forming, high molecular weight polymer and a water-insoluble silver halide developing agent and (2) an aqueous latex of a non-proteinaceous, alkali permeable, synthetic, film-forming, high molecular weight polymer having a water-insoluble silver halide developing agent absorbed by the said polymer particles.

18. An element of claim 17 having on the said support at least one silver halide emulsion.

19; A light-sensitive, silver halide photographic composition comprising a mixture of gelatin and a developer dispersion selected from the class consisting of (1) an oil-in-Water type emulsion comprising fine droplets dispersed throughout an aqueous phase of a low-boiling, water immiscible solvent having dissolved therein a non proteinaceous, alkali permeable, synthetic, film-forming, high molecular weight polymer and a water-insoluble silver halide developing agent and (2) an aqueous latex of a non-proteinaceous, alkali permeable, synthetic, filmforming, high molecular weight polymer having a waterinsoluble silver halide developing agent absorbed by the said polymer particles.

20. A photographic composition of claim 19 wherein the polymer is hydrophilic.

21. A composition of claim 19 wherein the polymer is a latex.

22. A composition of claim 19 wherein the polymer is a hydrophilic polymer having a molecular weight of from about 5,000 to about 500,000.

23. A photographic composition of claim 19 wherein the photographic composition is a silver halide emulsion.

24. A photographic element comprising a support having thereon the composition of claim 19.

25; A photographic element comprising a support having thereon the composition of claim 20.

References Cited UNITED STATES PATENT S 2,315,966 4/1943 'Knott 96-95 3,165,411 1/1965 Fox 96-114 3,260,598 7/1966 Yutzy et al 969 5 NORMAN G. TORCHIN, Primary Examiner J. R. HIGHTOWER, Assistant Examiner US. Cl. X.R. 96-95, 76 

